Expansible wheel



Dec. 10, 1929. F, TOWNSEND 7 1,739,271

' EXPANSIBLE WHEEL Filed March 1, 1928 2 Sheets-Sheet -1 flTTOR/VEYS Dec. 10, 1929. F. L. TOWNSEND EXPANSIBLE WHEEL Filed March 1, 1928 2 Sheets-Sheet 2 11v VEN T01? Zia/2f Z amizselzd.

WIT V553 Patented Dec. 10, 1929 UNITED STATES PATENT OFFICE FRANK L. TOWNSEND, OF HADDONIFIELD, NEW JERSEY, ASSIGNOR '10 AMERICAN EX PANSION WHEEL CORPORATION, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TTON OF DELAWARE EXPANSIBLE W HEEL Application filed March 1,

The present invention relates to expansible wheels, a principal object of the invention being to provide an expansible Wheel of improved construction and which in its preferred embodiment may be manufactured in great part from sheet metal stampings united Where necessary by spot Welding or the like with the result that the finished wheel though exceedingly strong is light in weight while the cost of manufacture is relatively low.

My invention further includes other ob jects and novel features of design, construction and arrangement hereinafter more particularly pointed out or which will be apparent from the accompanying drawings.

While wheels embodying the principles of my invention are adapted for many different purposes in the arts they are, among other things, eminently suitable for use as bufling wheels in which case a suitable annular band of abrasive or detergent material is disposed upon the periphery of the wheel. These bands are well known articles of commerce and are supplied in diiferent' sizes to the trade. Because of its capability for radial expansion in all directions, my improved wheel may therefore be verysatisfactorily employed as a support for these bands since by first contracting the wheel the desired band may be very readily disposed on its periphery and then secured in place by suitably expanding the wheel. To enable those skilled in the art to comprehend and practise the in vention I shall therefore herein refer more particularly to a wheel suitable forthi's purpose and which is illustrated in the drawings, in which Fig. 1 is aside elevation of the wheel mounted on a shaft and with an abrasive band disposed about its periphery, a. portion of one of the supporting disks being broken away to better illustrate the internal construction of the wheel, and Fig.2 is a transverse section through the wheel on line 22 in Fig. 1. Fig. 3 is a fragmentary detail section on line 33 in Fig. 2. Fig. 4 is a side elevation, partially broken away into section, of one of the wheel segments removed from the wheel and Fig. 5 is an end view of a slightly modified form of segment. The same symbols are used to designate cor- 1828. Serial No. 258,164.

responding parts in the different figures and the sectional views are to be understood as taken in the directions respectively indicated by the arrows on the section lines.

Referring now to the drawings the wheel therein illustrated comprises a pair of sup porting disks generally designated as A and B. The disk A comprises two complementary members, an outer member 3 and an inner member 4 telescoping therewith, both conveniently separately stamped from sheet metal and then united by spot welding, these two members being desirably of the shape best shown in Fig. 2, the disk thus present-,

ing a flat peripheral portion and a central cylindrical opening adapted for the reception of the expander E hereinafter more fully described. It will be noted that the inner memher 4 of the disk is so shaped that it forms the wall of this opening and thus provides a bearing for the expander on which the latter can slide longitudinally, while the outer disk has an inclined portion angularly extending from the fiat marginal part and thus forming a sort of strut between the margin of the disk and that portion of the inner member which surrounds the central opening, thereby enhancing the general rigidity of the disk. The extreme inner edge of the outer member of the disk is desirably bent over the adjacent edge of the inner member to form an inwardly projecting flange 7 which forms a stop for the expander eifective to limit its movement outwardly.

The other disk B is likewise composed of two complementary telescoping sheet metal members 8 and 9 and similarly provides a. flat marginal flange and a central opening adapted for the passage of the shaft 10 on which the wheel is mounted, this opening however being ordinarily of smaller diameter than the central opening in the other disk.

symmetrically disposed about the flat marginal portions of 'the disks which are provided with aligned holes for their reception; in the drawings live bolts are shown but any desired number thereof may be employed.

The expander E to which reference has been made is operatively disposed in the central openingin the diskA and surrounds the shaft 10. Like the disks, it is preferably formed from steel stampings and comprises an outer shell having acylindrical region 20 forminga good sliding fit in the central aperture of the disk A and a conical region 21 sloping inwardly from the cylindrical region toward the axis of the shaft. Within and spotwelded or otherwise secured to the shell is'a sleeve 22 which forms a good sliding fit on the shaft 10 while an annular stay piece 23 'desirablyof substantially U-shaped cross section is interposed between the sleeve and the shell at its rear or larger end and welded in position. It 'will thus be apparent that the expander when assembled on the shaft and in'the disk A as best shown in Fig. 2 is 7 free to move longitudinally on the shaft for a-limited distance while, additionally, though of relatively light weight it is nevertheless extremely rigid and resistant to radial pressure both on its cylindrical and on its conical surfaceswhich latter is preferably interiorly supportedand reinforced by the forward end of the sleeve which for this purpose is enlarged so'as'to seat against its inner surface.

Against the outer face of the diskB I preferablydispose a collar 25 which surrounds the shaft and'may 'abut against an annular flange 10"formedthereon,while adjacent the outer end of the expander I-dispose a substantially similar collar 26 which is adapted to bear against the end of the sleeve 22 and inner rim of the stayrpiece 23 as well as against thetouter rim of the latter while for forcingthis washer inwardly so as to move the expander in a corresponding direction, the end ofthe shaft 10 is threaded and provided with a nut 27 and, preferably, with a 'locknut28 as well to insure the retention ofthe nut 27 .in any desired posltion of adjustment The rim or periphery of the wheel is formed by a plurality"ofindependent radially movable segments S, ten of these being employedin'the particular embodiment of the invention illustrated although any desired number may be :utilized, and as all of these segments are identical a description of one of them-will suffice. Each segment is desirably formed of sheet metal and comprises two principal parts 30 and 31 which may be conveniently designated as the head and toe of the segment, each part being separately stamped or cut out to the proper shape and then bent upinto final form before they are spot welded or otherwise united together to form the completed segment. Thus the head or main outer portion of each segment comprises a segmental transversely flat rim 33 desirably provided at its edges with inward ly annularly directed flanges 34: with consequent formation of an under cut channel exteriorly of the rim while, from the extremities of the latter, the walls of the segment are directed inwardly in opposite directions as at 35 and then turned into parallel rela tion and continued to form extensions 36 which, viewed from the side as in Fig. 4, are relatively narrow in comparison with the rest of the head and have parallel edges for the major portion of their length, it being of course understood, as will be apparent from said-figure, that the ends 37 of the outer .portion of the segment beyond the extension .36 are radially directed and that the length of the segment between the said ends is such that when the several segments are assembled they will either be in contact at their ends or separated by a relatively narrow gap when the wheel is contracted. A stay piece 38 of substantially U-shaped cross section is desirably disposed between the side walls of the segment in alignment with the extensions 36.

The toe 31 of the segment is welded or otherwise secured between the lower ends of the extensions 36 and projects beyond the latter.

This toe viewed from the side as in Fig. f is substantially wedge shaped and is provided at its innerextremity with an inclined face or region 40 adapted to bear on the correspondingly inclined region 21 of the expander. The toe is also shaped to provide a laterally extending lug 41 adapted to bear against the inner face of the disk B. which is inwardly offset as shown in Fig. 2 in the region which is engaged by the lug sons to provide a circular depression 43 for its reception. Desirably, also,'the inclined end face 40 of the lug is curved transversely so as to seat more perfectly on the expander and thereby attain a maximum bearing thereon.

To insure true radial movement of the segments each of the latter is provided with a guide rib 45 struck outwardly on the face of the segment and adapted to seat'in a radially extending groove 46 formed in the inner face of the supporting disk A'as best shown in Fig. 8. If desired the segments may also be provided with suitably disposed struck-up strengthening ribs 48. r

To afford a suitable backing for the annular abrasive band X the undercut channel formed between the inclined flanges 3st of each segment may be filled with any suitable composition C such as hard rubber, fibre or the like, conveniently by molding the same into the segment and, if desired, a filler piece 49 may be secured to the outer face of the rim to assist in holding the composition in place as well as to decrease the amount of composition required to fill the channel.

In accordance with one method of assembling the wheel on the shaft, the collar 25 and disk B may first be positioned on the latter. The expander is then inserted in the disk A and these parts, followed in turn by the collar 26, are slipped over the shaft and the nuts 27, 28 then screwed loosely on the end thereof. The bolts 15 may then be put in place so as to properly align the collars and the nuts 16 threaded onto the ends of the bolts without, however, tightening the nuts enough to draw the disks so closely together as to prevent the insertion of the segments between them. The latter are now assembled in position by consecutively sliding them radially inward between the disks, care being taken to align the guide ribs 45 of the segments with and to enter them into the guide grooves 46 in the disk A. Nuts 16 may then be fully tightened so as to draw the disks together against the faces of the segments which are thereafter prevented from sliding radially outward sufficiently to get out of position by the engagement of the lugs 41 on the toes of the segments with the annular wall of the depression 43 in the disk B in which they are disposed.

Or, if desired and in accordance with an other method of assembly, the segments may be assembled with the disks and expander apart from the shaft and then, after the collar 25 is in place, may he slipped en dwise over the shaft and the collar 25 and nuts 27 and 28 disposed thereon. Frequently this method of assembly will be found more convenient than that hitherto described but whichever method be adopted, it is apparent that once the disks, bolts 15, expander and segments are assembled, they form a self-contained, unitary structure which may I readily be placed on or removed from the shaft when desired.

After the parts have been assembled on the shaft it is further apparent that by setting up on the nut 27, the collar 26 and in turn the expander may be forced longitudinally inward along the shaft, thus wedging the segments simultaneously radially outward through the engagement of their inclined regions 40 with the conical region of the expander, the extent of outward movement of the segments being of course limited by the diameter of the depression 43. Thus, the radially adjusted position of the segments is determined by the longitudinally adjusted position of the expander on the shaft which, in turn, is regulated by the position of nut 27 so that when the latter is backed off the wheel can be contracted by simply pressing inwardly on the segments to thereby enable the band X to be readily slipped over the periphery of the wheel. The nut 27 may then be tightened so as to move the segments radially outward until the pressure requisite to hold the band firmly in place is exerted.

It will be observed that the engagement of the lugs 41 with the inner face of the depressed portion 43 of the disk B affords effective resistance to the longitudinal thrust of the expander while the wheel is being expanded; in consequence the only movement which can be imparted to the segments by the expander is a radial one while, additionally, any tendency of the longitudinal thrust exerted by the expander is negatived. It will further be observed that because the extensions or inner ends of the segments are relatively narrow in comparison with the outer portions or heads thereof, gaps or spaces 50 of considerable width are left between the extensions which aiford ample room for the passage of the bolts 15 thus avoiding the necessity for slotting the segments for the passage of the bolts as might be required if the ends of each segment were disposed in continuous radial planes throughout their length, while, on the other hand, the ends 37 of the outer ends or heads of the segments at all times are either in contact or nearly so, as when the wheel is contracted to its maximum extent, or else separated by relatively narrow gaps 57.

Under ordinary conditions the frictional engagement between the shaft, flange 10, nut 27, collars 25 and 26 and parts adjacent thereto is sufficient to insure rotation of the wheel with the shaft but under certain conditions it may be desirable to positively secure the collar 25 and disk B to the shaft as by means of a key 52 or otherwise and thus avoid any possibility of relative rotation or slippage between the wheel and the shaft. In Fig. 5 I have showna modified form of segment suitable for use when it is desired to provide the wheel with a flat rim or pe riphery as, for example, when the wheel is to be used as a pulley for the reception of a belt. This form of segment is similar in all respects to that heretofore described except that the inclined flanges 34 as well as the filler piece 49 are omitted. If desired, one or more strengthening rigs 53 may be formed on the inner face of the rim to enhance its rigidity.

It is therefore apparent I have provided an expansible wheel of relatively light weight but which is, nevertheless, of extreme rigidity and strength and in which the diameter of the wheel may be readily varied, between limits, to enable a band to be firmly seated on its periphery or for other purposes as may be desired; that the wheel, irrespective of the adjusted position of the segments, at all times presents a truly cylindrical periphery since the segments are respectively constrained to move in radial paths during their adjustment and are at all times positively held in symmetrically disposed relation about the axis of the wheel; that because of the firm and rigid support afforded by the expander to the individual segments, the wheel is extremely resistant to inward radial pressure and thus capable of sustaining heavy loads without danger of collapse, and that because of the construction and arrangement of the several parts with resulting interfitting and interlocking engagement thereof, it is equally resistant to bursting when run at high speeds in buffing or other operations.

While I have herein illustrated and described one form of my invention with considerable particularity, I do not thereby desire or intend to limit myself specifically thereto for numerous modifications and changes may be made in the design and arrangement of the various parts and in their details of construction and assembly without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. An expansible wheel comprising a pair of opposed spaced disks, means operative to prevent axial separation of the disks, an expander seat-ed inone of the disks and longitudinally slidable with respect thereto, and a plurality of radially disposed segments each having a head portion disposed outside the peripheries of the disks and an extension disposed between the disks and adapted to bear on the expander.

2. An expansibl-e wheel comprising a pair of opposed spaced disks, means operative to prevent axial separation of the disks, an ex pander seated in one of'the disks and longitudinally slidable with respect thereto, a plurality of radially disposed segments each having ahead portion disposed outside the peripheries of the disks and an extension disposed between the disks and adapted to bear on the expander, and means operative to maintain each segment in radially aligned position.

3. An expansible wheel comprising a pair of opposed spaced disks, means operative to prevent axial separation of the-disks, an expander seated in one of the disks and longitudinally slidable with respect thereto, a plurality of symmetrically arranged movable segments each having a head portion disposed outside the peripheries of the disks and an, extension disposed between the disks and adapted to bear on the expander, means for limiting the outward movement of the segments, and means operative to constrain the segments to respectivelyv move in radial paths relatively to the disks.

a. An expansible wheel comprising a pair of opposed spaced disks, means operative to prevent axial separation of the disks, an expander having a conical surface seated in one of the disks and longitudinally slidable with respect thereto, a plurality of symmetrically arranged movable segments each having a head portion disposed outside the peripheries of the disks and an extension disposed between the disks and provided with a toe having an inclined region adapted to bear on the expander, means for limiting the outward movement of the segments, andmeans operative to constrain the segments to re spectiv-ely move in radial paths relatively to the disks.

5. In combination with a supporting shaft, a pair of disks surrounding the shaft and longitudinally spaced apart, an expander surrounding and slidable on the shaft and hav ing a conical surface, means operative to limit movement of the expander in one direction, means for limiting movement of one of the disks along the shaft in the other direction, means for preventing axial separation of the disks, a plurality of segments symmetrically arranged about the shaft and each having a head portion extending beyond the pe ripheries of the disks and a toe portion dis posed between the disks and having an inclined region adapted to bear on the expander, and means for moving the expander along the shaft in a direction to simultaneously force all of the segments radially outward through coaction of their inclined surfaces with the conical surface of the expander.

6. In combination with a supporting shaft, a pair of disks surrounding the shaft and longitudinally spaced apart, an expander mounted in one of the disks and having a conical surface, the expander surrounding and being slidable on the shaft, means operative to limit movement of the expander in one direction with respect to said disk, means for preventing axial separation of the disks, means for limiting movement of the other disk along the shaft in the other direction, a plurality of segments symmetrically arranged about the shaft and each having a head portion extending beyond the peripheries of the disks and a toe portion extending between the disks and adapted to bear on the conical surface of the expander, means for moving the expander along the shaft relatively to the disk in which it is mounted and. in a direction to simultaneously force all of the segments radially outward, means for constrainingthe segments to respectively move in radial paths, and means for limiting the outward movement of the segments.

In witness whereof, I have hereunto set my hand this 29th day of February, 1928.

. V FRANK L. TOWNSEND. 

